Uncaught RangeError: Invalid string length

The following line causes the string to become very large if there are a lot of tokens:
https://github.com/ant-design/cssinjs/blob/92dce00796e2644dad391b49ec1def849329234a/src/util.ts#L47

If the string becomes too long, it would exceed the capacity of the runtime system and raise an `Uncaught RangeError: Invalid string length` error.

Start by reading src/util.ts at line 47 and reproduce the failure with a large number of tokens. The issue does not name a test or specify the intended behavior; done should mean the large-token case no longer raises the reported uncaught RangeError, with coverage for that case if the existing test structure supports it.

Written by the indexing model from the issue text.